CN103996985A - Method for overhauling oil leakage existing on middle portion and lower portion of large transformer by means of pressure intensity balance - Google Patents

Method for overhauling oil leakage existing on middle portion and lower portion of large transformer by means of pressure intensity balance Download PDF

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Publication number
CN103996985A
CN103996985A CN201410257341.7A CN201410257341A CN103996985A CN 103996985 A CN103996985 A CN 103996985A CN 201410257341 A CN201410257341 A CN 201410257341A CN 103996985 A CN103996985 A CN 103996985A
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China
Prior art keywords
transformer
oil
cabinet
pressure
maintenance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201410257341.7A
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Chinese (zh)
Inventor
韦瑞峰
冉玉琦
陈振江
袁峻
张南辉
代正元
徐肖庆
李梦滔
董伟
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Kunming Power Supply Bureau of Yunnan Power Grid Co Ltd
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Kunming Power Supply Bureau of Yunnan Power Grid Co Ltd
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Application filed by Kunming Power Supply Bureau of Yunnan Power Grid Co Ltd filed Critical Kunming Power Supply Bureau of Yunnan Power Grid Co Ltd
Priority to CN201410257341.7A priority Critical patent/CN103996985A/en
Publication of CN103996985A publication Critical patent/CN103996985A/en
Pending legal-status Critical Current

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Abstract

The invention provides a method for overhauling oil leakage existing on the middle portion and the lower portion of a large transformer by means of pressure intensity balance. The method comprises the steps that transformer oil in a transformer box body is discharged; the transformer box body is vacuumized to enable negative pressure to be formed in the transformer box body, and oil pressure in the transformer box body is reduced to be balanced with the external atmospheric pressure; when the transformer oil in the transformer box body does not flow out or a small amount of transformer oil flows out, a manhole in the transformer box body is opened, and a sealing gasket or accessories are overhauled; after overhauling is completed, the dry air is added into the transformer box body, negative pressure does not exist, and transformer oil is poured into the transformer box body to reach the set oil level. According to the method for overhauling oil leakage existing on the middle portion and the lower portion of the large transformer by means of pressure intensity balance, the problems that the overhauling and power failure time for the sealing gasket and the accessories on the middle portion and the lower portion of the transformer is long, a large amount of oil needs to be discharged, and workloads are large are solved, the overhauling time is greatly shortened, overhauling can be completed within one day, the transformer is prevented from being affected with damp, the operating risk is reduced, and manpower and material resources are reduced.

Description

Application pressure equilibrium is overhauled in high-power transformer, the method for bottom leakage of oil
Technical field
The invention belongs to large-scale power transformer technical field, be specifically related to a kind ofly to apply in pressure equilibrium maintenance high-power transformer, the method for bottom leakage of oil.
Background technology
Leakage in Transformer oil defect happens occasionally, and accounts for the significant proportion of transformer equipment defect always.49 of my power supply administration transformer equipment deficiencies in 2012 according to statistics, 17 of leakage of oil defects account for 35% of sum; 65 of transformer equipment deficiencies in 2013,22 of leakage of oil defects account for 34% of sum.
Wherein the sealing gasket ageing failure of flange or butterfly valve is the main cause that produces leakage of oil, need to overhaul sealing gasket and could thoroughly process.For the sealing gasket service work at transformer top, only need to have a power failure 1 day, emit a small amount of oil in transformer top and just can carry out work, relatively easy.
But in high-power transformer, the sealing gasket of bottom, the sealing gasket below coil more changes jobs more thorny.Conventionally need to emit a large amount of transformer oil to needing below the sealing gasket position of maintenance, now transformer coil is exposed in atmosphere, bring the moistureproof dry and vacuum impregnating wet goods operation of coil, need to be undertaken by the program of transformer overhaul vacuum oil, drop into longer interruption duration, more human resources and vehicle utensil, wherein the transformer of 500kV need to have a power failure 8 days, and the transformer of 220kV need to have a power failure 5 days, and the transformer of 110kV need to have a power failure 3 days.So in high-power transformer, the defect of the aging leakage of oil of lower seal pad often can only simply clean shutoff, becomes leftover problem for many years.
The same relay when transformer or oil-immersed pump damage while needing maintenance, if the butterfly valve of both sides fits badly the problem that also existence need to be drained the oil in a large number.Therefore how overcoming the deficiencies in the prior art, is the problem that current large-scale power transformer technical field is needed solution badly.
Summary of the invention
For improving power supply reliability, improve repair quality, solve in transformer, lower seal pad and annex maintenance interruption duration is long, workload is large problem, here according to the principle of pressure equilibrium propose a kind ofly to apply in pressure equilibrium maintenance high-power transformer, the method for bottom leakage of oil, greatly shorten the repair time, in 1 day, can complete, simultaneously, the risk of having avoided transformer to make moist, and solve in high-power transformer maintenance, problem that lower seal pad, annex need be drained the oil in a large number.
The present invention has adopted following technical scheme: a kind ofly apply in pressure equilibrium maintenance high-power transformer, the method for bottom leakage of oil, it is characterized in that comprising the following steps:
1) emit transformer oil in transformer-cabinet to apart from casing top 100-200mm;
2) in the transformer-cabinet of step 1), vacuumize, make to form negative pressure in transformer-cabinet, reduce oil pressure in transformer-cabinet to outside atmosphere pressure balanced;
3) in the time that the transformer oil in transformer-cabinet can outwards not flow out or flow out less, open the manhole on transformer-cabinet, carry out sealing gasket or annex maintenance;
4) overhaul completely, in transformer-cabinet, fill into dry air, remove negative pressure, to injection transformer oil in transformer-cabinet to setting oil level.
The present invention specifically comprises the steps:
Step (1): close the valve between installation for transformer and Buchholz relay, then indicate transparent oil pipe to be connected with transformer-cabinet by fuel outlet valve oil pump and oil level;
Step (2): open fuel outlet valve, open oil pump, transformer oil is put to oil tank of transformer top cover, be limited not expose iron core; Then close the valve between transformer body and Buchholz relay, then between transformer body and Buchholz relay, vacuum pump is installed;
Whether step (3): open the valve of controlling vacuum pump, open vacuum pump, oil level, to overhauling desired location, stops vacuum pump work in oil level is indicated transparent oil pipe, observe pressure and change; If pressure is constant, pull down rapidly the annex or the sealing gasket that need maintenance, maintenance recovers rapidly; If have many places to need maintenance, should carry out one by one by order from top to bottom; If oil level rises rapidly after oil level can not drop to maintenance desired location or stop vacuum pump work, should check whether the negative pressure regions such as sleeve pipe top, vacuum pipe have seepage;
Step (4): after having overhauled, vacuum pump continues operation 20 ~ 40 minutes, then abolish negative pressure with dry air, then remove vacuum pump, recover Buchholz relay is installed, finally open the valve between installation for transformer and Buchholz relay, and the oil of emitting is supplemented to oil-feed pillow from conservator Fill valve, check whether transformer oil arrives setting oil level, from the repeatedly exhaust of each steam vent simultaneously.
In step (2), transformer oil is put to apart from casing top 100-200mm.
While maintenance in step (3), overhaul tapping with shrouding temporary plugging.
theoretical principle of the present invention:
Pressure equilibrium ratio juris is exactly to emit transformer oil in transformer-cabinet to apart from after the 100-200mm of casing top, vacuumize, make formation negative pressure in transformer-cabinet, reduce oil pressure in transformer-cabinet when with outside atmosphere pressure balanced, transformer oil in transformer-cabinet can outwards not flow out or few outflow, thereby can open the manhole on transformer-cabinet, so that maintenance sealing gasket or annex.
As shown in Figure 1, overhauled when needs are in the time that the perforate of transformer bottom is overhauled the pressure P=P of tapping transformer inside in the past 1+ P 2, because P 1≈ P 0so, P=P 1+ P 2> P 0, tapping transformer internal pressure is greater than external pressure, so cause transformer oil to leak outside in a large number, transformer oil need to be put to maintenance position of opening, could carry out service work.Now transformer coil is exposed in atmosphere, has brought the moistureproof dry and vacuum impregnating wet goods operation of coil, need to be by the program recovery oiling of transformer overhaul vacuum oil.
If we set up negative pressure with vacuum pump at transformer top, reduce transformer air pressure inside P 1, make P=P 1+ P 2=P 0time, tapping transformer internal pressure and external pressure balance, transformer oil will can not leak outside, and can carry out smoothly service work.The theoretical principle of pressure equilibrium method that Here it is.
1, the control of negative pressure value
Setting up negative pressure in transformer inside is in order to reduce transformer air pressure inside P 1if, transformer air pressure inside P 1reduce very fewly still can make transformer oil leak outside not reach the effect of requirement; Too much, have a large amount of air and enter transformer-cabinet if reduce, this is disadvantageous to transformer.So controlling the size of negative pressure value is the key of method.
1.1 monitor control by Pressure gauge meter
The size of negative pressure can monitor control by Pressure gauge meter.As shown in Figure 1, take Kunming as example, Kunming Areas atmospheric pressure P 0=80kPa, establishes transformer top pasta to the height h=3 rice that overhauls tapping, if will reach pressure equilibrium,
P 1=P 0-P 2=P 0oilgh=80000-895 × 9.8 × 3=53867Pa ≈ 54kPa
In formula: P 0---external atmosphere pressure
P 1---transformer air pressure inside
P 2---be highly the oil pressure of h
ρ oil---transformer oil density, 895kg/m 3
G---acceleration of gravity, 9.8N/kg
H---tapping is to fuel head, 3m
So only transformer internal gas pressure need be reduced to be controlled at 54kPa left and right.
1.2 intuitively monitor control by the principle of communicating pipe
Due to field condition more complicated, as atmospheric pressure is affected by height above sea level to differ to be decided to be standard value, the factor impact such as pressure meter reading parasitic error is large easily produces error in Practical Calculation and operation.Whether we can utilize the principle of communicating pipe to carry out intuitive judgment transformer air pressure inside and meet the demands.
Indicate one, transparent oil pipe to be connected in the fuel outlet valve of transformer bottom oil level, other end is fixed on higher than transformer oil bit position, opens fuel outlet valve, and transformer oil flows into transparent oil pipe to consistent with pasta line in transformer.Open vacuum pump, along with reducing of transformer internal gas pressure, oil level in oil pipe declines gradually, when oil level in oil pipe drops to the position of required maintenance perforate or pressure equilibrium inside and outside maintenance tapping transformer is described when lower slightly, now can stop vacuum pump work and carry out service work.
2, vacuumize the selection of position
Vacuumize from Buchholz relay: close the valve between installation for transformer and casing, bleed off a small amount of oil in transformer top, reserve certain space, to prevent transformer oil suction vacuum pump.The amount of draining the oil is limited not expose iron core, generally apart from transformer-cabinet top cover 100-200mm.Stop Buchholz relay, vacuumize from Buchholz relay.
The selection of this position is suitable for the transformer of various structures, in the time that vacuum pumping speed is enough fast, even when there is small seepage sleeve pipe top or other positions, also can meet the requirement of pressure equilibrium.
beneficial effect of the present invention is:(1) the present invention overhaul in high-power transformer, the method application pressure equilibrium principle of bottom leakage of oil, solved in transformer, lower seal pad and annex maintenance interruption duration is long, workload is large problem; (2) the inventive method has shortened the repair time greatly, in 1 day, can complete; (3) risk of having avoided transformer to make moist, the problem that simultaneously solved in high-power transformer maintenance, lower seal pad, annex need be drained the oil in a large number; (4) the inventive method is simple, and safety improves power supply reliability and repair quality, has reduced operating risk, has also greatly reduced man power and material's consumption.
Brief description of the drawings
Fig. 1 is the structural representation of transformer of the present invention, 1-transformer body; 2-maintenance department opening; 3-installation for transformer; 4-Buchholz relay; 5-valve; 6-oil pump; 7-oil level is indicated transparent oil pipe; 8-fuel outlet valve; 9-vacuum pump, 10-oil tank.
Embodiment
Below in conjunction with Fig. 1, the present invention is proposed a kind ofly apply in pressure equilibrium maintenance high-power transformer, the method for bottom leakage of oil is described further.
Main Work tool is prepared:
Large-scale vacuum unit 1 (joining corresponding pipeline, joint, power line), oil pump 1 (joining corresponding pipeline, joint, power line), oil level indicate that transparent oil pipe 1 overlaps, qualified makeup oil is appropriate, dry air 1 bottle of (joining corresponding pipeline, joint), 1,3T oil tank, 2, dirty oil drum, other general purpose tools and sealing gasket etc.
Embodiment 1
Apply in pressure equilibrium maintenance high-power transformer, the method for bottom leakage of oil, comprise the steps:
Step (1): close the valve 5 between installation for transformer 3 and Buchholz relay 4, then oil pump 6 and oil level are indicated transparent oil pipe 7 to be connected with transformer-cabinet 1 by fuel outlet valve 8;
Step (2): open fuel outlet valve 8, open oil pump 6 and take out transformer oil to oil tank 10, transformer oil is put to oil tank of transformer top cover, be limited not expose iron core; Then close the valve 5 between transformer body 1 and Buchholz relay 4, then between transformer body 1 and Buchholz relay 4, vacuum pump 9 is installed;
Step (3): open the valve 5 of controlling vacuum pump 9, open vacuum pump 9, indicate the interior oil level of transparent oil pipe 7 to overhauling desired location when oil level, overhaul tapping 2, stop vacuum pump 9 and work, observe pressure and whether change; If pressure is constant, pull down rapidly the annex or the sealing gasket that need maintenance, maintenance recovers rapidly; If have many places to need maintenance, should carry out one by one by order from top to bottom; If oil level rises rapidly after oil level can not drop to maintenance desired location or stop vacuum 9 pump works, should check whether the negative pressure regions such as sleeve pipe top, vacuum pipe have seepage; If maintenance needs the regular hour, use the perforate of shrouding temporary plugging;
Step (4): after having overhauled, vacuum pump continues operation 30 minutes, then abolish negative pressure with dry air, then remove vacuum adapter, vacuum pump and pipeline, recover Buchholz relay is installed, finally open the valve between installation for transformer and Buchholz relay, and the oil of emitting is supplemented to oil-feed pillow from conservator Fill valve, check whether transformer oil arrives setting oil level simultaneously, whether normal, from the repeatedly exhaust of each steam vent.
Embodiment 2
Embodiment 2 is with the difference of embodiment 1: step is opened fuel outlet valve 8 in (2), and transformer oil is put to the following 100mm of oil tank of transformer top cover; After having overhauled in step (5), vacuum pump continues operation 20 minutes; Remainder is identical with embodiment 1.
Embodiment 3
Embodiment 3 is with the difference of embodiment 1: step is opened fuel outlet valve 8 in (2), and transformer oil is put to the following 200mm of oil tank of transformer top cover; After having overhauled in step (5), vacuum pump continues operation 40 minutes; Remainder is identical with embodiment 1.
Embodiment 4
Embodiment 4 is with the difference of embodiment 1: step is opened fuel outlet valve 8 in (2), and transformer oil is put to the following 150mm of oil tank of transformer top cover; After having overhauled in step (5), vacuum pump continues operation 25 minutes; Remainder is identical with embodiment 1.
  

Claims (4)

1. apply in pressure equilibrium maintenance high-power transformer, the method for bottom leakage of oil, it is characterized in that comprising the steps:
1) emit the transformer oil in transformer-cabinet;
2) in the transformer-cabinet of step 1), vacuumize, make to form negative pressure in transformer-cabinet, reduce oil pressure in transformer-cabinet to outside atmosphere pressure balanced;
3) in the time that the transformer oil in transformer-cabinet can outwards not flow out or flow out less, open the manhole on transformer-cabinet, carry out sealing gasket or annex maintenance;
4) overhaul completely, in transformer-cabinet, fill into dry air, remove negative pressure, to injection transformer oil in transformer-cabinet to setting oil level.
2. in application pressure equilibrium according to claim 1 maintenance high-power transformer, the method for bottom leakage of oil, it is characterized in that in step 1) that transformer oil puts to apart from casing top 100-200mm.
3. in application pressure equilibrium according to claim 1 maintenance high-power transformer, the method for bottom leakage of oil, it is characterized in that specifically comprising the following steps:
Step (1): close the valve between installation for transformer and Buchholz relay, then indicate transparent oil pipe to be connected with transformer-cabinet by fuel outlet valve oil pump and oil level;
Step (2): open fuel outlet valve, open oil pump, transformer oil is put to apart from casing top 100-200mm, be limited not expose iron core; Then close the valve between transformer body and Buchholz relay, then between transformer body and Buchholz relay, vacuum pump is installed;
Step (3): open the valve of controlling vacuum pump, open vacuum pump and make to form negative pressure in transformer-cabinet, whether oil level, to overhauling position of opening, stops vacuum pump work in oil level is indicated transparent oil pipe, observe pressure and change; If pressure is constant, pull down rapidly the annex or the sealing gasket that need maintenance, after maintenance, return is installed again rapidly;
Step (4): after having overhauled, vacuum pump continues operation and stops after 20 ~ 40 minutes, then pass into dry air and in transformer-cabinet, abolish negative pressure, the work of recovery Buchholz relay, finally open the valve between installation for transformer and Buchholz relay, and the oil subsidy of emitting is charged into conservator, check whether transformer oil arrives to set oil level simultaneously, and each steam vent exhaust from transformer-cabinet.
4. in application pressure equilibrium according to claim 1 maintenance high-power transformer, the method for bottom leakage of oil, while it is characterized in that in step (3) maintenance with shrouding temporary plugging maintenance tapping.
CN201410257341.7A 2014-06-11 2014-06-11 Method for overhauling oil leakage existing on middle portion and lower portion of large transformer by means of pressure intensity balance Pending CN103996985A (en)

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Publication number Priority date Publication date Assignee Title
CN107204230A (en) * 2017-07-11 2017-09-26 嘉陵江亭子口水利水电开发有限公司 Sealing gasket replacing options and oil-filled transformer
CN108630421A (en) * 2018-04-24 2018-10-09 广州发展集团股份有限公司 Forced oil-circulation transformer oil-immersed pump replacing options
CN110349785A (en) * 2019-06-04 2019-10-18 平高东芝(河南)开关零部件制造有限公司 A kind of hydraulic operating mechanism method for maintaining
CN112837914A (en) * 2020-12-31 2021-05-25 国网湖南省电力有限公司 Device and method for on-site oil and gas supplement of high-voltage bushing of transformer
CN114242450A (en) * 2021-11-09 2022-03-25 天威保变(秦皇岛)变压器有限公司 Static discharge process and effect verification method for large oil-immersed transformer in high-altitude area

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CN203339529U (en) * 2013-05-14 2013-12-11 国家电网公司 All-in-one machine for changing transformer accessory

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107204230A (en) * 2017-07-11 2017-09-26 嘉陵江亭子口水利水电开发有限公司 Sealing gasket replacing options and oil-filled transformer
CN108630421A (en) * 2018-04-24 2018-10-09 广州发展集团股份有限公司 Forced oil-circulation transformer oil-immersed pump replacing options
CN110349785A (en) * 2019-06-04 2019-10-18 平高东芝(河南)开关零部件制造有限公司 A kind of hydraulic operating mechanism method for maintaining
CN112837914A (en) * 2020-12-31 2021-05-25 国网湖南省电力有限公司 Device and method for on-site oil and gas supplement of high-voltage bushing of transformer
CN112837914B (en) * 2020-12-31 2022-06-21 国网湖南省电力有限公司 Device and method for on-site oil and gas supplement of high-voltage bushing of transformer
CN114242450A (en) * 2021-11-09 2022-03-25 天威保变(秦皇岛)变压器有限公司 Static discharge process and effect verification method for large oil-immersed transformer in high-altitude area

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Application publication date: 20140820